In conventional manner, such a pallet is made of wood and generally comprises support planks on which goods are placed. The support planks are parallel to one another and they are held spaced apart from base planks which are likewise parallel to one another and to the support planks, by means of three cross spacer elements which are fixed to the base planks so as to interconnect them, with fixing being performed by nails passing through the support planks in the middle and at the ends. As a general rule, the spacer elements comprise three solid blocks, interconnected by top and bottom cross-members, and to which the support and base planks are fixed, respectively.
A drawback of such pallets is that they comprise a large number of elements (twenty-four for the most widespread pallet structure, namely: six support planks, three top cross-members, nine blocks, three bottom cross-members, and three base planks), which leads to assembly costs, labor costs, and stock management costs that are all relatively large. The time required for manufacture is also relatively long.
Furthermore, wooden pallets are relatively fragile and need to be repaired regularly. In addition, wooden pallets suffer from the drawback of taking up moisture, thereby increasing their weight. Furthermore, when a pallet stands on a damp surface, moisture tends to rise as far as the support planks and possibly also to reach the goods stored on the pallet.
An object of the invention is to propose a pallet of structure that is robust and simple.
To achieve this object, the invention provides a goods pallet comprising parallel support elements having at least end portions fixed by assembly means to cross-connection elements, each of which comprises a beam of channel section having a top flange to which the support elements are fixed, and a web and a bottom flange which are both recessed by at least one notch to form two spaced-apart brackets on either side thereof that are integral with the top flange.
A pallet made in this way is easily made by assembling together its various elements and it presents properties similar to those of conventional pallets, in particular wooden pallets, and possibly even better than those of pallets made of ordinary types of injected thermoplastic material. The channel section of the beam thus ensures good distribution of the weight supported by the pallet. In addition, this beam presents good mechanical strength because of its structure, thus making it possible, in particular compared with conventional wooden pallets, to avoid using a bottom cross-member uniting the brackets, which makes it possible to reduce the height of the pallet. In addition, by using such a beam, various portions of the conventional assembly are formed as a single piece (two cross-members and three blocks in the above-described prior art wooden pallet), thus reducing the number of parts and simplifying manufacture of the pallet. The cross beams can also be made out of materials which do not absorb moisture, thereby preventing moisture from rising into the goods supported by the pallet.
In a particular embodiment, the pallet comprises at least one stiffener element extending parallel to the support elements and at a distance therefrom between two opposite brackets, the stiffener element being formed by a plank-shaped beam, the bottom surface of the beam being grooved and the beam having at least one chamfer formed in at least one of its top longitudinal edges. The resulting pallet is thus particularly strong. This also makes it possible firstly to lighten the pallet and secondly to reduce the risk of impact between the stiffener element and the tips of forklift tines.
Advantageously, the cross beam comprises at least one reinforcing rib at at least one of its brackets, the reinforcing rib extending over the web between the top and bottom flanges.
The cross beam then presents increased resistance to the impacts that the tines of forklift trucks can impart against the web of the cross beam.
According to a particular characteristic, at least the cross beams are made out of a thermoplastic material.
New polyethylene terephthlate is a material that is frequently used to manufacture mass-produced products such as bottles or common consumer articles. Recycled polyethylene terephthlate, in particular when it comes from household waste, is often heterogeneous in nature having physico-chemical characteristics of relatively poor level, thereby restricting its use as a recycled product to manufacturing parts that are thin and of mediocre quality, and that are made out of materials incorporating only a small quantity thereof. Given the volumes of products made out of new polyethylene terephthlate and the difficulty in recycling this material, recycling all of the polyethylene terephthlate that is produced is not a practical possibility at present. This is amplified by the fact that recycled polyethylene terephthlate, and indeed ordinary quality new polyethylene terephthlate, is unsuitable for use in making bulky parts that are solid. As a result the quantity of polyethylene terephthlate that can be recycled in products is limited.
Thus, in the invention the thermoplastic material comprises:
recycled polyethylene terephthalate;
recycled high density polyethylene;
a compatibility agent; and
a reinforcing filler, and advantageously comprises, by weight:
approximately 49% to 63.5% and preferably 55% of polyethylene terephthalate;
approximately 27% to 36% and preferably 33% of high density polyethylene;
approximately 4% to 6% and preferably 5% compatibility agent; and
approximately 5% to 10% and preferably 7% of reinforcing filler.
This provides in simple manner a cross beam made of recycled material that is solid and bulky in structure. The part presents mechanical characteristics which are satisfactory, and in the preferred composition come close to those of wood, with this applying in particular to breaking strength, thereby enabling parts made of this material to be assembled in similar ways to wood.